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(11) | EP 0 158 048 A3 |
(12) | EUROPEAN PATENT APPLICATION |
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(54) | Mixing systems |
(57) @ Mixing systems for liquids having fibers suspended therein wherein the fibers tenaciously
adhere to and accumulate on the leading edge of an impeller (30), thereby increasing
the drag of the liquid on the impeller (30) as it rotates and the consequent increase
in the power required to rotate the impeller (30), is reduced. Axial flow of the liquid
in a tank (10) is produced by the impeller (30) within a draft tube (12). The leading
edge (38) of the blades (32) of the impeller (30) are inclined with respect to radial
lines (60) extending from the axis of rotation (56) of the impeller (30) beyond the
angle of repose of the fibers on the leading edge (38). Also, the coefficient of friction
of the portion of the impeller (30), extending from the leading edge (38) toward the
trailing edge (40) thereof, to which the fibers adhere is reduced by providing the
surface thereof with a low coefficient of friction material (50). |